Is the Enphase IQ8MC-72-M-INT compatible with the Enphase IQ Gateway Metered?

Yes — listed by the manufacturer.

The manufacturer's published pairing data lists these together.

Minute Solar records Enphase IQ8MC-72-M-INT with Enphase IQ Gateway Metered as compatible (A — Automatic). Derived from recorded specifications or compatibility groups; no manufacturer approval is recorded.

▦Manufacturer's compatibility listListed together in the manufacturer's published pairing data. A cited document reference is being added as datasheets are processed.